Mark Gibbs has a cool column on Network World where he compares a quote by George Lucas with developing software.

George Lucas has been quoted as saying that "A movie is never finished, only abandoned."

Software is never finished, it is release when deemed usable and new versions appear as features get added and bugs get fixed.

George is, as far as I know, one of the first directors to release new and improved versions of Star Wars, adding scenes as if he was adding features.